Globalizing Time: Hypothetical Navigation in Nineteenth-Century Japan

The modern notion of time in Japan was conceived during an imaginary journey in the open sea. Several decades before political reforms of the mid nineteenth century finally enabled the Japanese to sail abroad, some Japanese scholars had already begun contemplating long-distance sea voyages. While political restrictions at that time conveniently kept Japanese sailors within sight of coastal landmarks, scholars began to concern themselves with the question of determining longitude in the open sea. They pondered the changes that the sea would force them to make to their familiar method of extrapolating distance from the difference in time measurements of a single celestial event, and came to the conclusion that the problems which arose from their use of the pendulum clock could be avoided by using a Western chronometer. The chronometer not only offered solutions to mechanical troubles, it suggested a time that was markedly different from the kinds of times previously known in Japan. Unlike the commonly used hours of varied length, or the astronomical decimal time calculated from the local noon, or the idiosyncratic time of the pendulum oscillations, marine chronometer measured time that was independent of any human activity or even from the visible to the naked eye celestial motion — it was a mathematically calculated global mean time. Conceptualizing traveled distance as an interval between two points on the continuum of this universal time, Japanese scholars came up with the modern Japanese word for time—jikan. Lacking observational data of their own they were forced to rely on timings of longitudes found in English nautical almanacs, and growing accustomed to using Greenwich as a reference point they suggested that Japan should officially become a participant in the global time by adopting the Western standard.